Re: JNDI on AS400

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I'm not David but I'll tell ya what I did and maybe it will help.

I created the JNDI stuff, using Richard's code as a starting point.I
named it "StatementPoolingDataSource" I then created a servlet that is
loaded at startup of Tomcat. This servlet does the JNDI lookup int the
init method. I have public method getDataSource() that returns the
static DataSource that I looked up in the init method to any other
servlet or Java bean that needs a connection. .

Here is my init in the load-at-startup servlet:

  public void init(ServletConfig config) throws ServletException  {
   super.init(config);
   try {
       Context ctx = new InitialContext();
       dataSource = (DataSource) ctx.lookup("StatementPoolingDataSource");
    }
    catch (Exception e)
       {
          System.out.println(e);
    }
 }

Here is my getDataSource() method in the load-at-startup servet:

  public static DataSource getDataSource()  {
   return dataSource;
  }

Hope that helps, PLA

Alex Pinsky wrote:

>Hi David,
>I'm trying to replace our home written ConnectionPool class to manage JDBC 
>connections with the UDBConnectionPoolDataSource as explained by Richard 
>Dettinger in his January 2002 article in iSeries magazine. Right now we create 
>ConnectionPool in our Login servlet init() method (being called when Tomcat is 
>started) and place a reference to that object into ServletContext for future 
>reference by every servlet that needs a database connection. We have a static 
>class Pool with method getConnection() which performs a lookup for given 
>attribute name in a ServletContext for reference to the ConnectionPool object, 
>gets connection from the pool and return it to the requester. After use 
>servlet calls Pool.freeConnection(Connection con) which returns given 
>connection back to the pool.
>I want to create UDBConnectionPoolDataSource and use it as a connection 
>factory with the statement pooling. The problem that I see is that I have to 
>create ConnectionPoolDataSource first and than create standard data source to 
>reference it and I don't know how to do this without JNDI as shown in 
>Richard's example:
>       // Create a ConnectionPoolDataSource implementation
>       UDBConnectionPoolDataSource cpds = new UDBConnectionPoolDataSource();
>      cpds.setDescription("Connection Pooling DataSource object with Statement 
>pooling");
>      cpds.setMaxStatements(10);
>
>      // Establish a JNDI context and bind the connection pool data source
>      Context ctx = new InitialContext();
>      ctx.rebind("StatementSupport", cpds);
>
>
>      // Now create a standard datasource that references it.
>      UDBDataSource ds = new UDBDataSource();
>      ds.setDescription("DataSource supporting statement pooling");
>      ds.setDataSourceName("StatementSupport");
>      ctx.rebind("StatementPoolingDataSource", ds);
>
>I don't want to use JNDI because it is an expensive operation but it seems the 
>only way how to reference one type of object to another... Maybe you can help 
>me to figure-out this?
>By the way - after proper tuning (as you recommended) I got Tomcat4.1.12 
>working fine, thanks...
>
>Alex Pinsky
>Intranet developer
>Aeropostale, Inc.
>
>-----Original Message-----
>From: David Morris [mailto:David.Morris@plumcreek.com]
>Sent: Friday, December 13, 2002 2:04 PM
>To: java400-l@midrange.com
>Subject: Re: JNDI on AS400
>
>
>What are you sharing this connection with? Using JNDI is great
>if you have two components that don't know about each other,
>but there is a lot of overhead involved. You might consider
>creating your own cache for connections and putting a reference
>to them into a static locator. You can wrap that around your
>initial context if necessary to give you the best of both worlds.
>If I were to guess, I would say in your second example you used
>the wrong name in your lookup.
>
>David Morris
>
>
>
>>>>apinsky@aeropostale.com 12/13/02 10:30AM >>>
>>>>
>>>>
>This is a multi-part message in MIME format.
>--
>--
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>Hi,
>I'm trying to configure Tomcat to use UDBDConnectionPoolDataSource as
>statement pooled connection factory and can't get JNDI to work.
>Before run it under Tomcat I want to make sure that JNDI portion of the
>code would work. The code is:
>
>
>
>
>import java.sql.*;
>import javax.naming.*;
>import java.util.*;
>import com.ibm.db2.jdbc.app.UDBDataSource;
>
>
>public class UDBDataSourceExample1
>{
>    public static void main(java.lang.String[] args)
>    throws Exception
>    {
>        UDBDataSource ds = new UDBDataSource();
>        ds.setDescription("Basic DataSource");
>        System.out.println("dataSource created");
>
>
>        Context ctx = new InitialContext();
>
>
>        ctx.rebind("BaseDataSource", ds);
>    }
>}
>
>Error message when trying to rebind:
>javax.naming.NoInitialContextException:
>Need to specify class name in environment or system property, or as an
>applet parameter, or in an application resource file:
>java.naming.factory.initial
>....
>
>and if I'm running the same code with initial context set as:
>
>import java.sql.*;
>import javax.naming.*;
>import java.util.*;
>import com.ibm.db2.jdbc.app.UDBDataSource;
>public class UDBDataSourceExample1
>{
>    public static void main(java.lang.String[] args)
>    throws Exception
>    {
>        UDBDataSource ds = new UDBDataSource();
>        ds.setDescription("Basic DataSource");
>        System.out.println("dataSource created");
>        Hashtable env = new Hashtable();
>        env.put(Context.INITIAL_CONTEXT_FACTORY,
>                "com.sun.jndi.fscontext.RefFSContextFactory");
>        env.put(Context.PROVIDER_URL, "file:/jdbc/DataSources");
>        System.out.println("envelope created");
>
>        // Establish a JNDI context.
>        Context ctx = new InitialContext(env);
>        System.out.println("Context created");
>        ctx.rebind("BaseDataSource", ds);
>    }
>}
>javax.naming.NameNotFoundException; remaining name
>'"/jdbc/DataSources"'
>      java/lang/Throwable.<init>()V+4 (Throwable.java:78)
>      java/lang/Exception.<init>()V+1 (Exception.java:29)
>      javax/naming/NamingException.<init>()V+1
>(NamingException.java:112)
>      javax/naming/NameNotFoundException.<init>()V+1
>(NameNotFoundException.java 44...
>
>We are running V5R1 with all latest PTF installed and I run second
>example with fscontext.jar included in class path
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>_______________________________________________
>This is the Java Programming on and around the iSeries / AS400 (JAVA400-L) 
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